Response of Indian mustard (Brassica juncea L.) to nitrogen and phosphorus with and without gypsum in sodie soils irrigated with sodie water.

Effect of nitrogen and phosphorus fertilizer levels and gypsum was studied on the yield of Indian mustard (Brassica juncea L.) grown in sodic soil irrigated with sodic water. Treatments comprised of combination of two levels of gypsum viz. no gypsum (G0) and gypsum application (G100) based on 100% gypsum requirement of irrigation water and three levels of N (80, 100 and 120 kg N ha−1) as main plots. The sub-plot treatments consisted of three levels of P (30, 37.5 and 45 kg P2O5 ha−1). Indian mustard responded significantly up to 125% of the recommended dose of NP (100 kg N + 37.5 kg P2O5 ha−1) with gypsum application and up to 150% ofthe RD of NP (120 kg N + 45 kg P2O5 ha−1) without gypsum under sodic soil and water conditions. Indian mustard required 25 and 50% higher doses of NP under sodic soil and water conditions with and without gypsum application, respectively as compared to normal soil and water conditions for achieving optimum economical yield under semi-arid climatic conditions of the south-western part of Haryana. Gypsum application also improved chemical properties of the soil in terms of marginal decrease in pH, exchangeable sodium percentage, maintenance of organic carbon content and build up of available P status of the soil.